[Bug] Doubly defined objects in the output specification #260

[allComputableThings]

When we have:

@component
@dataclasses.dataclass
class Location:
    x: int
    y: int
@component
@dataclasses.dataclass
class UserProfile:
    name: str
    age: int
    email: str
    location: Location #Path

Location is define twice in the output schema. Once in components, once again within UserProfile.

This is deeply problematic for code generators which depend on generating a single class for both. ( openapi-generator-cli, for example, produces two Location classes and one cannot be used where the other is used).

UserProfile should have a ref to Location and Location should be added as a component whether or not it has the @component decorator:

{
   "$ref": f"#/components/schemas/{Location.__name__}"
}

import os
import dataclasses

from sanic import Sanic, text, Request
from sanic_ext.extensions.openapi import openapi
from sanic_ext.extensions.openapi.definitions import Response, RequestBody
from sanic_ext.extensions.openapi.openapi import component

# from typing import List

app = Sanic("app")

@component
@dataclasses.dataclass
class MyBody:
    email: str
    # @property
    # def something(self) -> int:
    #     print("Oh no you didn't!")
    #     return "OK2"

@component
@dataclasses.dataclass
class Location:
    x: int
    y: int


@component
@dataclasses.dataclass
class UserProfile:
    name: str
    age: int
    email: str
    # locations: List[Location] #Path
    location: Location #Path

    @property
    def something(self) -> int:
        print("Oh no you didn't!")
        return "OK"




@app.post("/")
@openapi.definition(
    body=RequestBody({"application/json": {
                    "$ref": f"#/components/schemas/{MyBody.__name__}"
                }}, required=True),  # if body else None,
    # body=RequestBody(Body, required=True),
    # summary="User profile update",
    # tag="one",
    # description=openapi.description(textwrap.dedent(func.__doc__)) if func.__doc__ else None,
    response=[  # Success,
        Response({
            "application/json": {
                "schema": {
                    "$ref": f"#/components/schemas/{UserProfile.__name__}"
                }
            }
        }, status=200)
        # Response(Failure, status=400)
    ],
)
def root(req: Request, *args, **kw):  # body:UserProfile):
    """
    Short description

    Long Description
    """
    return text("Hello")

ref: sanic-org/sanic-openapi#260

[allComputableThings]

Similarly: sanic-org/sanic-openapi#259

import dataclasses

from sanic_ext.extensions.openapi import openapi

@dataclasses.dataclass
class Path:
    x: [float]
    y: [float]

    @property
    def reversed(self) -> "Path":  # Recurses
        return Path(
            x=self.x[::-1],
            y=self.y[::-1],
        )
    
openapi.component(Path)   # Infinite loop

...

  File "/home/sir/venv/py3/lib/python3.10/site-packages/sanic_ext/extensions/openapi/types.py", line 446, in _extract
    hints = get_type_hints(item.fget)
  File "/usr/lib/python3.10/typing.py", line 1871, in get_type_hints
    value = _eval_type(value, globalns, localns)
  File "/usr/lib/python3.10/typing.py", line 327, in _eval_type
    return t._evaluate(globalns, localns, recursive_guard)
  File "/usr/lib/python3.10/typing.py", line 694, in _evaluate
    eval(self.__forward_code__, globalns, localns),
  File "<string>", line 1, in <module>
RecursionError: maximum recursion depth exceeded while calling a Python object

This is failing due to:

#openapi/types.py

        return cls(
            {
                k: Schema.make(v, **extra.get(k, {}))
                for k, v in _properties(value).items()          # Does not need to inspect properties for dataclass or Pydantic objects
            },
            **kwargs,
        )

It similarly fails without recursion:

import dataclasses
from typing import Tuple, List
from sanic_ext.extensions.openapi import openapi

@dataclasses.dataclass
class Path:
    x: [float]
    y: [float]

    @property
    def points(self) -> List[Tuple[float, float]]:
        pass

openapi.component(Path)

...

Traceback (most recent call last):
  File "/home/sir/venv/py3/lib/python3.10/site-packages/sanic_ext/extensions/openapi/types.py", line 417, in _properties
    annotations = get_type_hints(cls)
  File "/usr/lib/python3.10/typing.py", line 1856, in get_type_hints
    raise TypeError('{!r} is not a module, class, method, '
TypeError: typing.Tuple[float, float] is not a module, class, method, or function.

There's really no need for sanic to inspect property return types to discover model attributes. Dataclasses, Pydantic or type annotations on the class constructor all provide what is needed.

[allComputableThings]

I have a fix both, do you want a PR?